Re: [PATCH v6 2/4] dmaengine: mediatek-cqdma: remove redundant queue structure

From: Vinod Koul
Date: Wed Jul 15 2020 - 02:20:04 EST


On 02-07-20, 15:06, EastL Lee wrote:

> static enum dma_status mtk_cqdma_tx_status(struct dma_chan *c,
> dma_cookie_t cookie,
> struct dma_tx_state *txstate)
> {
> - struct mtk_cqdma_vchan *cvc = to_cqdma_vchan(c);
> - struct mtk_cqdma_vdesc *cvd;
> - struct virt_dma_desc *vd;
> - enum dma_status ret;
> - unsigned long flags;
> - size_t bytes = 0;
> -
> - ret = dma_cookie_status(c, cookie, txstate);
> - if (ret == DMA_COMPLETE || !txstate)
> - return ret;
> -
> - spin_lock_irqsave(&cvc->vc.lock, flags);
> - vd = mtk_cqdma_find_active_desc(c, cookie);
> - spin_unlock_irqrestore(&cvc->vc.lock, flags);
> -
> - if (vd) {
> - cvd = to_cqdma_vdesc(vd);
> - bytes = cvd->residue;
> - }
> -
> - dma_set_residue(txstate, bytes);

any reason why you want to remove setting residue?

> -static void mtk_cqdma_free_active_desc(struct dma_chan *c)
> +static int mtk_cqdma_terminate_all(struct dma_chan *c)
> {
> struct mtk_cqdma_vchan *cvc = to_cqdma_vchan(c);
> - bool sync_needed = false;
> + struct virt_dma_chan *vc = to_virt_chan(c);
> unsigned long pc_flags;
> unsigned long vc_flags;
> + LIST_HEAD(head);
> +
> + /* wait for the VC to be inactive */
> + if (!wait_for_completion_timeout(&cvc->cmp, msecs_to_jiffies(3000)))
> + return -EAGAIN;
>
> /* acquire PC's lock first due to lock dependency in dma ISR */
> spin_lock_irqsave(&cvc->pc->lock, pc_flags);
> spin_lock_irqsave(&cvc->vc.lock, vc_flags);
>
> - /* synchronization is required if this VC is active */
> - if (mtk_cqdma_is_vchan_active(cvc)) {
> - cvc->issue_synchronize = true;
> - sync_needed = true;
> - }
> + /* get VDs from lists */
> + vchan_get_all_descriptors(vc, &head);
> +
> + /* free all the VDs */
> + vchan_dma_desc_free_list(vc, &head);
>
> spin_unlock_irqrestore(&cvc->vc.lock, vc_flags);
> spin_unlock_irqrestore(&cvc->pc->lock, pc_flags);

Good cleanup, do you need both these locks?
--
~Vinod